The present invention relates to pavement markers of the type employing cube corner reflex reflectors which are placed on highways for indicating the highway centerline or highway lanes. Pavement markers have become very widely accepted in highway traffic control as means for providing highly visible signals, particularly in combination with conventional painted traffic lines of white or yellow. The pavement markers that have been provided in the past are typically embedded in the surface of the roadway by providing saw cuts in the surface or by providing large diameter drill cuts in various combinations. In practice, accordingly, the cost of installation of prior art reflector devices has been extremely high and has been a significant factor in the success or failure of marketing such devices.
Prior art patents such as U.S. Pat. No. 3,333,327 to Sidney A Heenan provided a prismatic retro reflector of the cube corner type mounted on the surface of the highway by an adhesive. Experience has shown that installation of the reflective device only upon the surface of the roadway has been inadequate in snow areas and, accordingly, markers utilizing various saw cuts, and the like, have been developed. For example, structures such as shown in the later Heenan U.S. Pat. No. 4,195,945 and Flanagan U.S. Pat. No. 4,155,667 have provided relatively complex marker embedding systems. The complexity of the roadway cuts as well as the complexity of the marker base employed therewith, has been excessively costly and, accordingly, disadvantageous for extensive highway use.